两种微波辅助萃取法萃取牛蒡多糖

以远红外干燥的牛蒡粉为原料，运用敞口常压微波和密闭高压微波两种辅助提取方法通过单因素和正交试验对牛蒡多糖的提取工艺进行对比研究，在鲜牛蒡60℃干燥、粉碎过40 目筛、纯水溶剂条件下，分别确定最佳工艺参数为常压微波功率250W、料液比1:25、提取100s，多糖提取率28.84%；高压微波功率90W、料液比1:35、控制压力0.4MPa、提取160s，多糖提取率31.97%，均高于热水回流浸提6h 的24.18% 提取率。微波萃取方法具有简单及萃取效率高等优点，经研究发现，高压微波的效果更好。

Comparison Study of Microwave-assisted Extraction of Polysaccharide from Burdock Roots under Normal and High Pressures

The microwave-assisted extraction of polysaccharide from dried burdock root powder below 40 mesh was separately performed under normal atmospheric and closed high pressures. One-factor-at-a-time and L9(34) orthogonal array methods were employed for optimizing two extraction procedures of polysaccharide from burdock roots. Maximum polysaccharide yields of 28.84% and 31.97% were obtained by extraction for 100 s at 250 W microwave power and normal pressure with a material/water ratio of 1:25 and by extraction for 160 s at 90 W microwave power and 0.4 MPa pressure with a material/water ratio of 1:35, respectively, both of which were higher than the yield of 24.18% by hot water reflux extraction for 6 h. All these results indicate that microwave-assisted extraction is a simple and rapid method, and microwave extraction combined with high pressure technology is more efficient.